Pilot light attachement for an electric switch

ABSTRACT

A pilot light attachment which may be installed on an electric switch without tools. The attachment is particularly suited for use with a manually operated motor-starter-type switch and includes a pair of springlike members that supply the force for maintaining the switch and attachment assembled and an electric connection between the switch and attachment. The portion of the attachment supporting the bulb is connected to the switch by a three-point suspension which spaces the attachment from the current-carrying parts of the switch to provide the switch current-carrying parts with a maximum convective cooling.

United States Patent [72] Inventors JamesP.Schmiedel Brown Deer; Don J.Arneberg. Milwaukee, both 01, Wis. [21] Appl. No. 9,159 [22] Filed Feb.6, 1970 [45] Patented Aug. 3, 1971 [73] Assignee Square D Company ParkRidge, 111.

[54] PILOT LIGHT ATTACHEMENT FOR AN ELECTRIC SWITCH 10 Chilns,.4 DrawingFigs.

[52] US. CL... 200/167 A [51] lnt.Cl. H0lh9/18 [50] Field 01 Search200/167 A;

[56] References Cited UNITED STATES PATENTS 3,270,164 8/ 1966 Schubring335/202 X 3,272,981 9/1966 O'Brien 200/167 A 3,294,945 12/1966McLaughlin 200/167 A 3,308,260 3/1967 Krieger et a1. 200/167 A X3,354,415 11/1967 Gribble et a1. 335/132 X 3,359,396 12/1967 Day ZOO/H5A Primary Examiner-H. 0. Jones Attorneys-Harold J. Rathbun and WilliamH. Schmeling ABSTRACT: A pilot light attachment which may be installedon an electric switch without tools. The attachment is particularlysuited for use with a manually operated motor-startertype switch andincludes a pair of springlike members that supply the force formaintaining the switch and attachment assembled and an electricconnection between the switch and attachment. The portion of theattachment supporting the bulb is connected to the switch by athree-point suspension which spaces the attachment from thecurrent-carrying parts of the switch to provide the switchcurrent-carrying parts with a maximum convective cooling.

PATENTEU AUG 3 Ian FIG-.3

'INVENTOR.

JAMES P. SCHMIEDEL DON J. ARNEBERG FIG.4

PILOT LIGHT ATTACHEMENT FOR AN ELECTRIC SWITCH This invention relates toelectric switches and more particularly, to a pilot light attachmentwhich may be installed and removed from the switch without the use oftools.

Heretofore, manually operated switches, such as contactors and the like,have been provided with pilot lights for indicating when the contacts ofthe switch are closed and the power circuit controlled by the switch isenergized. In pilot light structures as previously used, conventionallyseparate mounting means have been employed to attach the pilot lightstructure to other supporting structures. Further, the wires leadingfrom the pilot light were connected to terminals of the switch so thepilot lightwould be energized whenever the switch was in an ONcircuit-closing position. Thus, the prior art devices required the useof tools to mount the pilot light per se and achieve the electricalconnection between the switch and the pilot light. In the deviceaccording to the present invention, the use of tools which have beenheretofore required to mount the pilot light, have been completelyeliminated,.so that the device may be conveniently installed or removedfrom the basic switch and merchandised as a separate item which may beconveniently mounted on the switch when required.

It is an object of the present invention to provide a pilot lightattachment for a manually operated switch which may be readily installedon the switch without tools and without disturbing any components of theswitch.

Another object is to provide a pilot light attachment for an electricswitch wherein the attachment is maintained in position in the switch bya pair of resilient members that also provide an electrical connectionbetween the current-carrying parts of the switch and the pilot lightattachment.

An additional object is to provide a manually operated electric switchwith a pilot light attachment that may be installed on the switchwithout tools and will indicate when the switch is in a circuit-closingcondition without reducing the convective cooling of the currentcarrying parts of the switch.

A still further object is to provide a three-point mounting between anelectric switch and a pilot light attachment for the switch and tomaintain the three-point mounting by a pair of members that also providean electrical connection between the current-carrying parts of theswitch and the pilot light attachment.

Further objects and features of the invention will be readily apparentto those skilled in the art from the specification and appended drawingillustrating certain preferred embodiments in which:

FIG. 1 is a front plan view of an electric switch which may be used witha pilot light attachment that incorporates the features of the presentinvention.

FIG. 2 is a bottom end view of the switch in FIG. 1.

FIG. 3 is a side view of the switch with a pilot light attachment with aportion of the switch and the pilot light at tachment broken away.

FIG. 4 is a perspective view of the pilot light attachment detached fromthe switch in FIG. 3.

A switch 10, as shown in the drawing, preferably is of the type fullydisclosed in an application for U.S. Pat., Ser. No. 9,203, which hasbeen filed by the inventor Jordan F. Puetz concurrently herewith and hasbeen assigned to the assignee of the present application. As disclosedin the Puetz application, the switch includes a switching section 12 andan overload-detecting section 14. The switching section 12 includes ahousing 16 that is removably secured to a portion 18 of a base 20. Theoverload-detecting section 14 includes a portion 22 of the base 20. Thebase 20 preferably is formed as an integrally molded part which isformed to have a row of spaced compartments in each of the portions 18and 22 and has a rear wall 24 arranged to be mounted on vertical panel,not shown, by suitable screws which extend through openings 26 in thebase. The portion 22 of the base 20 has a front surface 28 whichprovides entry into the compartments in the portion 22. Each of thecompartments is arranged to include a solder type current responsiveunit which are designated in the respective compartments by the numerals30, 32 and 34.

Each of the current responsive units 30, 32 and 34 has a heater elementconnected in a circuit to be monitored and a ratchet wheel which is heldstationary when the current flow through the heating element does notexceed a predetermined value. The heater elements and the ratchet wheelsin the current responsive units 30, 32 and 34 are respectivelydesignated with a suffix a and b in the drawing. The heater elements30a, 32a and 34a each have their upper ends, as illustrated in FIG. 1,connected to a conductive strap by a screw 36 and their lower endsconnected-to individual terminal members 38 by a screw 40 so as to beheated by the current flow passing between the conductor strap that isconnected to the screws 36 and the terminal members 38. The heatingelements 30a, I 32and 34a when subjected to an excess current willrelease the respective ratchet wheels 30b, 32b and 34b so as to permitany one of a plurality of sliders, not shown, to move within the portion22 and cause a release of a trip mechanism within the switching section12 so that a toggle mechanism within the section 12 will move to atripped position and cause movable contacts within the switching section12 to separate from the stationary contacts so as to interrupt thecircuit therebetween. The conductive straps 50, to which the currentresponsive units 30 and 34 are connected respectively, have portionsdesignated by numerals 42 and 44 exposed to the front surface 28. Theportions 42 and 44 are each positioned within a socket defined byvertical walls 46 which form a continuation of partitions which definethe partitions in the base 20 defining the compartments wherein thecurrent responsive units 32 and 34 are located. The conductive straps 50also have a portion 47 to which a stationary contact 48 of the switchingsection 12 is attached.

The housing 16 and a portion of the base 18 form an internal cavitywherein the compartments provided by the base 20 are included.Positioned in each of the compartments is a pair of stationary contactsthat are spaced equidistantly on 0p posite sides of a centerline. Thestationary contacts adjacent the upper end of the switch are eachelectrically connected to a terminal member 52. The stationary contactsadjacent the lower ends of the compartments of the base 18, asillustrated by the stationary contact 48 in FIG. 3, are connected to theportion 47 of the conductive strap 50 so that the current responsiveunits 30, 32 and.34 may be electrically connected to the stationarycontacts of the switch by the screws 36. The housing 116 provides anenclosure for a movable contact carrier which is moved by a togglemechanism, not shown, from a position wherein movable contacts carriedby the carrier are separated from the stationary contacts into aposition wherein the movable contacts engage the stationary contactswhen the toggle mechanism is actuated. The toggle mechanism is actuatedby an OFF operating button 54 and an ON operating button 56, each ofwhich has a portion externally accessible of the switching section 12.The depression of the OFF button 54 will actuate the toggle mechanism sothat the movable contacts move to a position where they are separatedfrom the stationary contacts. The operation of the ON button will causethe toggle mechanism to move the movable contacts into engagement withthe stationary contacts to complete circuits through the currentresponsive units 30, 32 and 34.

The housing 16 has a wall 58 extending perpendicular to the top surface28. lntegrally formed as a portion of the housing 16 on the wall 58 arethree spaced abutments respectively designated by numerals 60, 62 and64. The abutments 60, 62 and 64 respectively have bottom surfaces 66, 68and 70 facing the front surface 28. Extending upwardly in the bottomsurfaces 66, 68 and 70 are grooves 72, 74 and 76, which respectivelyprovide surfaces 78, and 82. The surfaces 78,80 and 82 each confrontsand is vertically spaced from the front surface 28. The abutments 60 and64 are located on the housing 16 so that the surfaces 78 and 82 arespaced from each other and are equidistant from the front surface 28.The abutment 62 is positioned on the wall 58 so that the surface 80 andthe surfaces 78 and 82 are unequally spaced from the front surface 28and the surface 80 is equidistantly spaced between the surfaces 78 and82.

A pilot lamp attachment 90 for the switch includes a molded body 92, apair of leaflike spring members 94, a bulb receptacle 96, a pair ofleads 98, an incandescent bulb 100 and a support 102 for the bulbreceptacle 96. The molded body has a front surface 104, a rear surface106, a top end 108 and a bottom end 110, Extending between the frontsurface 104 and the rear surface 106 is a rectangularly shaped opening112 which is included to aid in the convective cooling of the currentresponsive unit 32 mounted in the central compartment in the base whenthe pilot light attachment 90 is secured on the switch 10. Extendingfrom the front surface 104 at the top end 108 of the molded body 92 arethree spaced tongues 114, 116 and 118. The tongues 114, 116 and 118 havefree ends which are arranged to be respectively received within thegrooves 72, 74 and 76 when the pilot light attachment 90 is positionedon the switch 10. The pair of leaflike spring members 94 are secured tothe rear surface 106 on opposite sides of the rectangular opening of thebody 92. The leaflike members 94 are formed of resilient metal materialand have leg portions 122 and 124 which extend rearwardly from the rearsurface 106 at the top end 108 of the body 92. The legs 122 and 124 eachhave a free end curved to provide a foot which are respectivelydesignated as 122a and 124a on the ends of the legs 122 and 124. Thebulb receptacle 96 is mounted on the bottom end 110 by the support 102which extends between the bottom end 108 and a bottom end of thereceptacle 96. The receptacle 96 extends parallel to the front surfaceand has a socket at its top end which receives the bulb 100. Extendingfrom the rear end of the receptacle are the pair of leads 98 each ofwhich has a slip-on type connector 126 on its terminal end. Theconnectors 126 on the pair of leads 98 are 'each connected to a portion120 on the pair of leaflike spring members so as 0 provide an electricalconnection between the pair of members 94 and the bulb 100. The members94 extend along the rear surface 106 so the portions 120 are located atthe bottom end 110 to permit the connection between the leads 98 and themembers 94 to be readily established during the manufacture of the pilotlight attachment 90. The legs 122 and 124 are arranged to position thefeet 122a and 124a so that the feet are pressed in tight engagement withthe portions 42 and 44 of the conductive straps 50 and to form anelectrical connection with the portions 42 and 44 on the conductivestraps 50 when the pilot lamp attachment 90 is secure in its position onthe switch 10. if required the receptacle 96 may also include a portion128 wherein a resistor which is electrically in circuit with the bulb100 may be included in a manner well known to those skilled in the art.

The pilot lamp attachment 90 is installed in its position on the switch10 by manually positioning the attachment 90 so that the feet 1220 and1240 are received in the sockets wherein the portions 42 and 44 of theconductive straps 50 are located. When the attachment is thuspositioned, it may be secured in its mounted position on the switch 10by moving the body 92 toward the front surface 28 against the forcesupplied by the resilient legs 122 and 124 to a position which willpermit the tongues 114, 116 and 118 to be respectively received withinthe grooves 72,74 and 76 as the top end 108 is positioned adjacent thewall 58. When the manual force on the body 92 is removed, the resiliencyprovided by the legs 122 and 124 will cause the tongues 114, 116 and 118to move into the grooves 72, 74 and 76 so that the free ends of thetongues 114, 116 and 118 engage the surfaces 78, 80 and 82 and maintainthe attachment 90 in its position on the switch 10. In this connectionit should be noted that the groove 74 and the tongue 116 are spaced fromthe front surface 28 at a grater distance than are the surfaces 78 and82 and the tongues 114 and 118. Thus the grooves 72, 74 and 76 and thecooperating tongues 114, 116 and 118 will provide a three-pointsuspension between the body 92 and the wall 58 to prevent the body 92from moving from its attached position on the switch 10. it is to befurther noted that when the attachment is secured on the switch 10, therear surface 106 will extend parallel to and be spaced from the frontsurface 28 to maximize the convective cooling to the current responsiveunits 30, 32 and 34. Additionally, all that is required to remove thepilot light attachment 90 from the switch 10 is to release theengagement between the tongues 114, 116 and 118 and the grooves 72, 74and 76 by merely forcing the body 92 rearwardly against the forcesupplied by the resilient leaflike spring members 94 so that the tongues114, 116 and 118 may be disengaged from the grooves 72, 74 and 76. Theremoval of the pilot light attachment may be required to inspect orinterchange the current responsive units 30, 32 and 34. When the switch10 together with its attached pilot lamp attachment 90 is energized, theportions 42 and 44 will have opposite polarity potentials impressedthereon. Thus, the bulb will be illuminated by a circuit that iscompleted through the members 94 because of the electrical connectionthat is established between the feet 122a and 124a which are pressedagainst the portions 42 and 44 so the electrical connection between thepilot light is established automatically when the pilot light attachment90 is mounted on the switch 10.

While certain preferred embodiments of the invention have beenspecifically disclosed, it is understood that the invention is notlimited thereto, as many variations will be readily apparent to thoseskilled in the art and the invention is to be given its broadestpossible interpretation within the terms of the following claims.

What we claim is:

1. A pilot light attachment for an electric switch, said switch having apair of spaced conductors exposed on a front surface and a plurality ofspaced grooves with each of said grooves providing a surface confrontingand spaced vertically from the front surface, said attachmentcomprising: an insulating body having a front side, a rear side and aplurality of tongues extending from the front side into engagement withthe surfaces provided by the plurality of spaced grooves, a pilot lightbulb, a receptacle for the bulb positioned by the body so the bulb isexposed from the front side, a pair of leads extending from thereceptacle for connecting the bulb in a circuit, and a pair of leaflikespring members each having a first end mounted on the rear surface andconnected to one of the leads and a second end engaging one of thespaced conductors for resiliently pressing the tongues into theplurality of spaced grooves and electrically connecting the bulb to thespaced conductors.

2. The structure as recited in claim 1 wherein the switch has twomutually perpendicular surfaces with one of the two surfaces providingthe front surface including a pair of sockets wherein the spacedconductors are disposed and the other of the two surfaces providing asupport for the plurality of spaced grooves.

3. The structure as recited in claim 2 wherein the plurality of spacedgrooves equal three with two of said three grooves providing a pair ofsurfaces that are spaced from each other and equidistant from the frontsurface of the switch and the third of the three grooves providing asurface that is equidistant to the surfaces of the said pair of grooves.

4. The structure as recited in claim 3 wherein the body has two endswith one of said two ends providing a support for the receptacle and theother of said two ends extending to provide a portion of each of thetongues.

5. The structure as recited in claim 4 wherein a plurality of currentresponsive units are mounted on the front surface and the insulatingbody has an opening therein aligned with one of the current responsiveunits to aid in the convection cooling of the said one currentresponsive unit.

6. The structure as recited in claim 4 wherein the receptacle extendsalong an axis that is parallel to the front side.

7. The structure as recited in claim 4 wherein the resilient members arearranged so the other of said two ends of the each extend in the samedirection from the front side of the body and one of the tongues isequidistantly spaced between two otherof said tongues. I

- 10. The structure as recited in claim 9 wherein the said one tongue isspaced at a greater distance from the front side than the said other twotongues.

1. A pilot light attachment for an electric switch, said switch having apair of spaced conductors exposed on a frOnt surface and a plurality ofspaced grooves with each of said grooves providing a surface confrontingand spaced vertically from the front surface, said attachmentcomprising: an insulating body having a front side, a rear side and aplurality of tongues extending from the front side into engagement withthe surfaces provided by the plurality of spaced grooves, a pilot lightbulb, a receptacle for the bulb positioned by the body so the bulb isexposed from the front side, a pair of leads extending from thereceptacle for connecting the bulb in a circuit, and a pair of leaflikespring members each having a first end mounted on the rear surface andconnected to one of the leads and a second end engaging one of thespaced conductors for resiliently pressing the tongues into theplurality of spaced grooves and electrically connecting the bulb to thespaced conductors.
 2. The structure as recited in claim 1 wherein theswitch has two mutually perpendicular surfaces with one of the twosurfaces providing the front surface including a pair of sockets whereinthe spaced conductors are disposed and the other of the two surfacesproviding a support for the plurality of spaced grooves.
 3. Thestructure as recited in claim 2 wherein the plurality of spaced groovesequal three with two of said three grooves providing a pair of surfacesthat are spaced from each other and equidistant from the front surfaceof the switch and the third of the three grooves providing a surfacethat is equidistant to the surfaces of the said pair of grooves.
 4. Thestructure as recited in claim 3 wherein the body has two ends with oneof said two ends providing a support for the receptacle and the other ofsaid two ends extending to provide a portion of each of the tongues. 5.The structure as recited in claim 4 wherein a plurality of currentresponsive units are mounted on the front surface and the insulatingbody has an opening therein aligned with one of the current responsiveunits to aid in the convection cooling of the said one currentresponsive unit.
 6. The structure as recited in claim 4 wherein thereceptacle extends along an axis that is parallel to the front side. 7.The structure as recited in claim 4 wherein the resilient members arearranged so the other of said two ends of the body is pressed intoengagement with the said other of said two surfaces of the switch whenthe second ends of the resilient members are in engagement with thespaced conductors.
 8. The structure as recited in claim 4 wherein thereceptacle provides a support for a resistor that is electrically incircuit with the bulb.
 9. The structure as recited in claim 4 whereinthe tongues each extend in the same direction from the front side of thebody and one of the tongues is equidistantly spaced between two other ofsaid tongues.
 10. The structure as recited in claim 9 wherein the saidone tongue is spaced at a greater distance from the front side than thesaid other two tongues.